Self-sealing internal manhole chimney seal

ABSTRACT

An assembly internally seals a manhole against infiltration of water. A pleated sleeve, made of an resilient material, includes a first and second sealing sections at opposite ends. The first sealing section has a lip that forms a recess for receiving an inwardly projecting flange on a frame of the manhole to attach the sleeve in a watertight manner. A fastening device engages the second sealing section and presses an outer surface of the sleeve against a different portion of the manhole to form another watertight seal.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to articles for internally sealing achimney of a manhole against ground water infiltration, and moreparticularly to mechanisms by which the seal is attached to the manhole.

2. Description of the Related Art

A typical manhole includes a main chamber or barrel section to which thesewer pipes connect. That section is topped with a conical riser inwhich the diameter reduces going upward to a size needed to fit a metalframe for the manhole surface opening. The metal frame receives themanhole cover and either sits directly on top of the riser or there maybe one or more vertical adjusting rings there between, as needed toraise the top of the frame level with the surrounding surface. Adjustingrings usually are formed by annular precast concrete sections or coursesof bricks or blocks. This combination of components is referred to as a“chimney”.

During construction of the manhole, the joints between the chimneycomponents are sealed with mortar or other material to prevent surfacewater infiltration. Nevertheless, movement of the metal frame, resultingfrom expansion and contraction due to seasonal temperature changes andfrom vibration as vehicles pass over the manhole, causes cracks to format those joints. As a result, ground water from rain and snow is able toenter the manhole through these cracks. Such ground water infiltrationis undesirable for sanitary sewers, as it increases the volume ofeffluent which has to be processed by a sewage treatment plant.Municipalities go to great lengths to minimize the inflow andinfiltration of ground water into sanitary sewers.

As a consequence, different external and internal sealing systems havebeen devised to prevent ground water infiltration into manholes. Onetype of an internal sealing system is described in U.S. Pat. No.4,469,467 and utilizes a resilient sleeve that is inserted into themanhole chimney and held against the inside surface by upper and lowermetal fastening bands.

SUMMARY OF THE INVENTION

An assembly is provided to internally seal a manhole againstinfiltration of water, wherein the manhole includes an inwardlyprojecting flange.

The assembly comprises a sleeve made of a resilient material whichincludes a first sealing section and a second sealing section. The firstsealing section has a recess for receiving the flange to attach thesleeve to the manhole. In a preferred embodiment, the first sealingsection is formed with a hook-like lip that creates the recess and theresiliency of the sleeve enables the lip to engage the flange in amanner that provides a watertight seal.

A fastening device engages the second sealing section of the sleeve andpresses an outer surface of the sleeve against a surface of the manhole,thereby providing another watertight seal. The preferred embodiment ofthe fastening device comprises a fastening band that has first andsecond end portions which overlap and a mechanism that adjustablysecures those end portions together to form a loop. For example, thefirst end portion has a tab and the second end portion has a pluralityof slots that cooperate with the tab to connect the first and second endportions together in the loop.

Another aspect of the assembly provides a pleated section between thefirst and second sealing sections to allow the sleeve to expand andcontract with movement of the parts of the manhole without breaking thewatertight seals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of the upper section of a manholehaving an internal chimney seal according to the present invention;

FIG. 2 is an enlarged portion of FIG. 1 showing details of how an upperend of the internal chimney seal is secured to the manhole;

FIG. 3 is another enlarged portion of FIG. 1 that illustrates how alower end of the internal chimney seal engages the manhole;

FIG. 4 is a fastening band that secures the lower portion of theinternal chimney seal to the manhole;

FIG. 5 is a cross section through the fastening band along line 5-5 FIG.3; and

FIG. 6 shows an installation tool being used to expand the fasteningband inside the manhole chimney.

DETAILED DESCRIPTION OF THE INVENTION

With initial reference to FIG. 1, a manhole 10 has a chimney 14 thatcomprises a conical riser 12 typically formed of precast concrete, butwhich may be laid bricks or blocks. Above the riser 12 are two precastconcrete, plastic or rubber adjusting rings 16 on top of which is ametal manhole frame 18. The number of adjusting rings 16 varies so thatthe chimney 14 has a height that places the upper end of the frame 18level with the ground surface 20. The conical riser 12, adjusting rings16, and manhole frame 18 are held together by mortar 15 or a suitableadhesive.

The metal frame 18 has an opening 22 by which a person gains access tothe interior of the manhole 10. An interior, annular flange 24 extendsaround the interior of the opening 22. A manhole cover 26 is shownclosing the upper portion of the opening 22 above the annular flange 24.The cover 26 is dropped in place and the annular flange 24 prevents thecover from falling completely through the opening 22.

An internal chimney seal 30 is attached inside the manhole 10 to providea watertight barrier at the joints between the manhole frame 18, theadjusting rings 16, and the riser 12, thereby blocking ground waterinfiltration. The seal 30 consists of a tubular sleeve 32 thatpreferably is constructed of rubber or a similar resilient material thatis extruded as a strip. The extruded strip is cut to a length thatcorresponds to the circumference of the finished sleeve and the endsthen are sealed together with a suitable adhesive, for example. Theexemplary sleeve 32 has two central pleats 33 and 34 located in betweencylindrical sealing sections 35 and 36 at opposite ends of the sleeve.The pleats 33 and 34 allow the sleeve to expand, thereby accommodatingvertical movement of the manhole components. Additional pleats or astraight section may be placed between pleats 33 and 34 to provide asleeve that is able to span taller manhole chimneys.

With reference to FIG. 2, the upper sealing section 35 of the sleeve 32is adapted to engage the interior annular flange 24 of the manhole frame18. Specifically a hook-like lip 40 extends around the upper end of thesleeve 32, thereby forming a recess 38 in the outer circumference of theupper sealing section 35. The resilient property of the sleeve 32 andthe size of the recess 38 provide a tight engagement of the hook-likelip 40 with the annular flange 24 of the manhole frame 18, that securesthe components together with a watertight seam.

In addition to providing a watertight seal to the manhole chimney frame18, the lip 40 of the sleeve 32 also acts as gasket between the manholecover 26 and the chimney frame to prevent water infiltration throughthat seam. As seen in FIG. 1, the lip 40 extends over the upper surfaceof the annular flange 24 in the opening 22 of the chimney frame 18.Therefore when the manhole cover 26 is dropped into the frame opening22, the cover compresses the sleeve lip 40 providing a seal between thecover and the chimney frame 18. Thus the novel internal chimney seal 30incorporates an integral cover gasket.

Referring to FIGS. 1 and 3, the lower sealing section 36 of the sleeve32 has outer circumferential surface 42 that engages and conforms to theinterior surface 44 at the upper portion of the conical riser 12. Thatouter circumferential surface 42 is formed by plurality of outwardlyprojecting annular fins 50 which extend around the sleeve 32 and engagethe conical riser's interior surface 44. The fins 50 deform when thelower sealing section 36 is pressed against the inner surface of themanhole 10, thereby conforming to irregularities in that manhole surfaceto provide a watertight seal. Specifically, each fin 50 has an edge ortip that contacts the interior surface of the manhole and has a sectionspaced from that edge which is adapted to deform as the fin is pressedagainst the manhole.

The fins 50 of the lower sealing section 36 are held against the innersurface of the manhole 10 by a stainless steel fastening band 48 that isreceived in an annular groove on the inner circumferential surface 46 ofthe lower sealing section 36. The fastening band 48 has overlapping endportions 51 and 52 which are slidable with respect to each other, asshown in FIG. 4. After the resilient sleeve 32 is properly locatedwithin the manhole 10, the fastening band 48 is expanded within thesleeve to press the finned outer periphery of the lower sealing section36 against the inner surface of the manhole riser 12. The resiliency ofthe sleeve 32 allows the lower sealing section to expand against themanhole wall and form an annular seal which prevents water flow therebetween.

Referring to FIGS. 1 and 6, expansion of the fastening band 48 isperformed by a scissors type tool 65 that is placed into apertures 66and 67 in the fastening band 48. As the fastening band 48 is expanded bythe tool 65, an angled tab 68 (see FIG. 5) on one end portion 51sequentially ratchets into a plurality of slots 70 spaced along theother end portion 52. Specifically a bolt 72 on the tool is turned by awrench to spread part two legs 74 and 75 that pivot about pin 76 on thetool 65. The remote ends of the legs 74 and 75 have hooks that fit intothe apertures 66 and 67 in the fastening band 48. After the fasteningband 48 has expanded sufficiently to provide the water tight seal, thebolt 72 is turned in the opposite direction to draw the legs 74 and 75together so that the tool 65 can be disengaged from the fastening band.The fastening band and the expansion tool are described more fully inU.S. Pat. No. 5,496,128, which description is incorporated herein byreference.

The foregoing description was primarily directed to a preferredembodiment of the invention. Although some attention was given tovarious alternatives within the scope of the invention, it isanticipated that one skilled in the art will likely realize additionalalternatives that are now apparent from disclosure of embodiments of theinvention. Accordingly, the scope of the invention should be determinedfrom the following claims and not limited by the above disclosure.

1. An assembly for internally sealing a manhole against infiltration ofwater, wherein the manhole includes an inwardly projecting flange, theassembly comprising: a sleeve made of an resilient material and having afirst sealing section and a second sealing section, the first sealingsection having a recess for receiving the flange to attach the sleeve tothe manhole, and the second sealing section having an outer surface; anda fastening device engaging the second sealing section and pressing theouter surface against a surface of the manhole.
 2. The assembly asrecited in claim 1 wherein the first sealing section comprises anannular lip which forms the recess.
 3. The assembly as recited in claim2 wherein the annular lip provides a seal between a manhole cover andthe flange.
 4. The assembly as recited in claim 1 wherein the firstsealing section comprises a hook-like lip which extends around thesleeve and forms the recess.
 5. The assembly as recited in claim 1wherein the flange is received in the recess of the first sealingsection in a manner that provides a watertight seal.
 6. The assembly asrecited in claim 1 wherein the sleeve further comprises a plurality ofpleats between the first sealing section and the second sealing section.7. The assembly as recited in claim 1 wherein the outer surface of thesecond sealing section comprises a plurality of annular fins extendingoutwardly around the sleeve.
 8. The assembly as recited in claim 7wherein each of the plurality of fins has an edge for contacting thesurface of the manhole and has a section spaced from the edge andadapted to deform as the fin is pressed against the surface of themanhole enabling the fin to conform to irregularities in the manhole. 9.The assembly as recited in claim 7 wherein the section of each of theplurality of fins is hollow.
 10. The assembly as recited in claim 1wherein fastening device comprises a fastening band engaging the secondsealing section.
 11. The assembly as recited in claim 10 wherein thefastening band has a first end portion and second end portion whichoverlap, and has a mechanism that adjustably secures the first andsecond end portions together to form a loop.
 12. The assembly as recitedin claim 10 wherein the fastening band has a first end portion with atab projecting therefrom, and second end portion with a plurality ofslots that cooperate with the tab to connect the first and second endportions together to form a loop.
 13. An assembly for internally sealinga manhole against infiltration of water, wherein the manhole includes aframe with an opening for access to inside the manhole and an annularflange projecting inwardly around the opening, the assembly comprising:a sleeve made of an resilient material and including a first sealingsection and a second sealing section, the first sealing section having alip that forms a recess for receiving the flange to attach the sleeve tothe frame of the manhole, and the second sealing section having an innersurface and an outer surface; and a single fastening band, wherein thesingle fastening band engages the inner surface of the second sealingsection and presses the outer surface against a surface of the manhole.14. The assembly as recited in claim 13 wherein first sealing sectionprovides a watertight seal with respect to the frame when the flange isreceived in the recess.
 15. The assembly as recited in claim 13 whereinthe lip provides a seal between a manhole cover and the flange.
 16. Theassembly as recited in claim 13 wherein the sleeve further comprises aplurality of pleats between the first sealing section and the secondsealing section.
 17. The assembly as recited in claim 13 wherein theouter surface of the second sealing section comprises a plurality ofannular fins extending outwardly around the sleeve.
 18. The assembly asrecited in claim 17 wherein each of the plurality of fins has an edgefor contacting the surface of the manhole and has a section spaced fromthe edge and adapted to deform as the fin is pressed against the surfaceof the manhole enabling the fin to conform to irregularities in themanhole.
 19. The assembly as recited in claim 17 wherein the section ofeach of the plurality of fins is hollow.
 20. The assembly as recited inclaim 13 wherein the fastening band has a first end portion and secondend portion which overlap and further including a mechanism thatadjustably secures the first and second end portions together to form aloop.
 21. The assembly as recited in claim 13 wherein the fastening bandhas a first end portion with a tab projecting therefrom, and second endportion with a plurality of slots that cooperate with the tab to connectthe first and second end portions together to form a loop.
 22. Theassembly as recited in claim 1 wherein the fastening device is the onlyfastening device that engages the sleeve.